1. Field of Invention
The invention relates to a data-repairing method for an optical disk, and more particularly to a method for repairing the DVD video/audio defects generated in the DVD instantaneous video/audio editing and recording system.
2. Related Art
The DVD-Video Mode and DVD-Video RM Mode files recorded through various kinds of DVD instantaneous video/audio editing and recording platforms generate some problems, such as ‘error fast forward play’, and ‘error play time displaying’. This is because correct values can not filled into the specific columns in Presentation Control Information (PCI) and Data Search Information (DSI) of the Navigation Pack of Video Object Sets (VOBS) of DVD video/audio files.
For example, the end presentation time of video object unit (VOBU_E_PTM, End PTM of VOBU) and sequence end presentation time of video object units (VOBU_SE_E_PTM, End PTM of sequence end in VOBU) in PCI General Information Table (PCI_GI) in Presentation Control Information (PCI), record end presentation time. These two fields inform the DVD decoder of end presentation time.
For Data Search Information (DSI), errors occur in the DSI General Information Table (DSI_GI), such as end address of VOBU (VOBU_EA), end address of the first Reference Picture in VOBU (VOBU—1STREF_EA), end address of the second Reference Picture in VOBU (VOBU—2NDREF_EA), and end address of the third Reference Picture in VOBU (VOBU—3RDREF_EA). The recorded addresses are not the same because of different length of each VOBU. Therefore, the fast forward or search function cannot perform normally in un-compatible players.
The values in these fields cannot be obtained in advance and be controlled in the decoding hardware and software in the instantaneous editing and recording platform. Different pictures and audios result in inconsistent pack length of the whole VOBU. These values are not obtained until the whole VOBU or VOB are finished editing.
Two solutions solve these technology bottlenecks. The first solution is using buffers. A large buffer is created to accommodate video/audio data upon the instantaneous editing and recording of the rewritable disks. Therefore, the navigation pack sector is reserved in the beginning. The navigation pack is generated after the video pack and the audio pack are recorded to a predetermined volume, and the navigation pack sector is filled into the reserved area.
The aforementioned method is feasible for VOBU_E_PTM, VOBU_E_PTM, VOBU—1STREF_EA, VOBU—2NDREF_EA, VOBU—3RDREF_EA, and VOBU_SE_E_PTM. One VOBU needs about 200 packs (400 KByte), which all the current platforms can reserve. However, for VOBU_SRI, a large buffer of 240 VOBUs (48 M Bytes) is needed, which is not easily to be coordinated among the various editing and recording platforms.
The second solution is to fix the length of each VOBU upon the instantaneous editing and recording of the rewritable disks. Since the length of each VOBU is different, a padding pack is needed to fix the length of each field in VOBU. However, the recordable time reduces. Furthermore, too many padding packs result in video/audio discontinuity and mosaic. Therefore, the second method is not very feasible.